The present invention relates to an electrophotographic photoconductor comprising a support and a photoconductive layer formed on the support, more particularly to an electrophotographic photoconductor comprising a support made of a phenol resin which releases substantially no ammonia or a minimized amount of ammonia.
Currently organic electrophotographic photoconductors comprising a support and a photoconductive layer comprising an organic photoconductive material formed on the support are more used than inorganic electrophotographic photoconductors comprising a support and an inorganic photoconductive layer containing an inorganic photoconductive material therein. This may be because such inorganic electrophotographic photoconductors are produced by a very costly method, such as vacuum deposition and glow discharge, particularly when forming its photoconductive layer. In contrast to this, in the organic electrophotographic photoconductors, the photoconductive layer can be produced by a less costly coating method and accordingly the organic electrophotographic photoconductors are less expensive than the inorganic electrophotographic photoconductors.
However, even if the cost for forming an organic photoconductive layer on a support is less than that for forming inorganic photoconductive layer, the cost of the support for use in the organic electrophotographic photoconductor is still high and predominant in the total cost of the organic electrophotographic photoconductor and therefore there is a demand for an inexpensive support for organic electrophotographic photoconductors.
For the purpose of meeting this demand, Japanese Laid-Open Patent Application No. 58-30764 proposes a pipe made of a phenol resin as the support of an organic electrophotographic photoconductor as meeting the requirements for such photoconductors, such as being light in weight, electroconductive, non-magnetic, and heat resistant and having high dimensional stability. There are two types of phenol resin, a resol type and a novolak type. It is considered that the novolak type is better than the resol type in the dimensional stability, surface properties and workability.
However, an electrophotographic photoconductor comprising a support in the shape of a pipe made of a novolak type phenol resin, an undercoat layer, a charge generating layer, and a charge transporting layer, which layers are successively overlaid on the support, has the shortcomings that the photosensitivity is poor and the residual potential increases while in use.